Fluorinated water repellent agents having fluorine-containing groups are conventionally known, and textile products imparted with water repellency on the surface, which are produced by treating textile products or the like with such fluorinated water repellent agents, are known. Such a fluorinated water repellent agent is generally produced by polymerizing or copolymerizing a monomer having a fluoroalkyl group.
Textile products that have been treated with fluorinated water repellent agents exhibit excellent water repellency; however, in order to manifest water repellency, it is necessary to arrange the orientation of fluoroalkyl groups. Therefore, after a fluorinated water repellent agent is attached to a textile product, the textile product must be heat-treated at a temperature of higher than 130° C. However, since a heat treatment at high temperature requires much energy, this poses a problem in the global movement of saving energy.
Furthermore, since monomers having fluoroalkyl groups are expensive, it is not satisfactory from the viewpoint of economic efficiency, and moreover, monomers having fluoroalkyl groups also have an environmental problem because the monomers have low degradability.
Meanwhile, in the field of water repellent processing of textile product, a water repellent agent that can provide excellent water repellency to a textile product even at a low concentration or a low heat treatment temperature is desired in view of the stabilization of product quality and cost reduction.
Thus, in recent years, research on non-fluorinated water repellent agents that do not contain fluorine is underway. For example, Non-Patent Literature 1 discloses a water repellent agent in which hydrocarbon compounds such as paraffin or waxes, a fatty acid metal salt, or an alkylurea is emulsified and dispersed.
Furthermore, Patent Literature 1 suggests a water repellent agent in which a particular non-fluorinated polymer is emulsified and dispersed, for the purpose of providing water repellency that is comparable to conventional fluorinated water repellent agents.